Merge pull request #24699 from ziglang/bounded

remove RingBuffer; remove BoundedArray; use `@memmove`

Author: andrewrk

doc/langref/test_switch_dispatch_loop.zig

@@ -8,20 +8,22 @@ const Instruction = enum {
 };
 
 fn evaluate(initial_stack: []const i32, code: []const Instruction) !i32 {
-    var stack = try std.BoundedArray(i32, 8).fromSlice(initial_stack);
+    var buffer: [8]i32 = undefined;
+    var stack = std.ArrayListUnmanaged(i32).initBuffer(&buffer);
+    try stack.appendSliceBounded(initial_stack);
     var ip: usize = 0;
 
     return vm: switch (code[ip]) {
         // Because all code after `continue` is unreachable, this branch does
         // not provide a result.
         .add => {
-            try stack.append(stack.pop().? + stack.pop().?);
+            try stack.appendBounded(stack.pop().? + stack.pop().?);
 
             ip += 1;
             continue :vm code[ip];
         },
         .mul => {
-            try stack.append(stack.pop().? * stack.pop().?);
+            try stack.appendBounded(stack.pop().? * stack.pop().?);
 
             ip += 1;
             continue :vm code[ip];

lib/docs/wasm/markdown/Parser.zig

@@ -29,13 +29,14 @@ const Node = Document.Node;
 const ExtraIndex = Document.ExtraIndex;
 const ExtraData = Document.ExtraData;
 const StringIndex = Document.StringIndex;
+const ArrayList = std.ArrayListUnmanaged;
 
 nodes: Node.List = .{},
-extra: std.ArrayListUnmanaged(u32) = .empty,
-scratch_extra: std.ArrayListUnmanaged(u32) = .empty,
-string_bytes: std.ArrayListUnmanaged(u8) = .empty,
-scratch_string: std.ArrayListUnmanaged(u8) = .empty,
-pending_blocks: std.ArrayListUnmanaged(Block) = .empty,
+extra: ArrayList(u32) = .empty,
+scratch_extra: ArrayList(u32) = .empty,
+string_bytes: ArrayList(u8) = .empty,
+scratch_string: ArrayList(u8) = .empty,
+pending_blocks: ArrayList(Block) = .empty,
 allocator: Allocator,
 
 const Parser = @This();
@@ -86,7 +87,8 @@ const Block = struct {
             continuation_indent: usize,
         },
         table: struct {
-            column_alignments: std.BoundedArray(Node.TableCellAlignment, max_table_columns) = .{},
+            column_alignments_buffer: [max_table_columns]Node.TableCellAlignment,
+            column_alignments_len: usize,
         },
         heading: struct {
             /// Between 1 and 6, inclusive.
@@ -354,7 +356,8 @@ const BlockStart = struct {
             continuation_indent: usize,
         },
         table_row: struct {
-            cells: std.BoundedArray([]const u8, max_table_columns),
+            cells_buffer: [max_table_columns][]const u8,
+            cells_len: usize,
         },
         heading: struct {
             /// Between 1 and 6, inclusive.
@@ -422,7 +425,8 @@ fn appendBlockStart(p: *Parser, block_start: BlockStart) !void {
             try p.pending_blocks.append(p.allocator, .{
                 .tag = .table,
                 .data = .{ .table = .{
-                    .column_alignments = .{},
+                    .column_alignments_buffer = undefined,
+                    .column_alignments_len = 0,
                 } },
                 .string_start = p.scratch_string.items.len,
                 .extra_start = p.scratch_extra.items.len,
@@ -431,15 +435,19 @@ fn appendBlockStart(p: *Parser, block_start: BlockStart) !void {
 
         const current_row = p.scratch_extra.items.len - p.pending_blocks.getLast().extra_start;
         if (current_row <= 1) {
-            if (parseTableHeaderDelimiter(block_start.data.table_row.cells)) |alignments| {
-                p.pending_blocks.items[p.pending_blocks.items.len - 1].data.table.column_alignments = alignments;
+            var buffer: [max_table_columns]Node.TableCellAlignment = undefined;
+            const table_row = &block_start.data.table_row;
+            if (parseTableHeaderDelimiter(table_row.cells_buffer[0..table_row.cells_len], &buffer)) |alignments| {
+                const table = &p.pending_blocks.items[p.pending_blocks.items.len - 1].data.table;
+                @memcpy(table.column_alignments_buffer[0..alignments.len], alignments);
+                table.column_alignments_len = alignments.len;
                 if (current_row == 1) {
                     // We need to go back and mark the header row and its column
                     // alignments.
                     const datas = p.nodes.items(.data);
                     const header_data = datas[p.scratch_extra.getLast()];
                     for (p.extraChildren(header_data.container.children), 0..) |header_cell, i| {
-                        const alignment = if (i < alignments.len) alignments.buffer[i] else .unset;
+                        const alignment = if (i < alignments.len) alignments[i] else .unset;
                         const cell_data = &datas[@intFromEnum(header_cell)].table_cell;
                         cell_data.info.alignment = alignment;
                         cell_data.info.header = true;
@@ -480,8 +488,10 @@ fn appendBlockStart(p: *Parser, block_start: BlockStart) !void {
         // available in the BlockStart. We can immediately parse and append
         // these children now.
         const containing_table = p.pending_blocks.items[p.pending_blocks.items.len - 2];
-        const column_alignments = containing_table.data.table.column_alignments.slice();
-        for (block_start.data.table_row.cells.slice(), 0..) |cell_content, i| {
+        const table = &containing_table.data.table;
+        const column_alignments = table.column_alignments_buffer[0..table.column_alignments_len];
+        const table_row = &block_start.data.table_row;
+        for (table_row.cells_buffer[0..table_row.cells_len], 0..) |cell_content, i| {
             const cell_children = try p.parseInlines(cell_content);
             const alignment = if (i < column_alignments.len) column_alignments[i] else .unset;
             const cell = try p.addNode(.{
@@ -523,7 +533,8 @@ fn startBlock(p: *Parser, line: []const u8) !?BlockStart {
         return .{
             .tag = .table_row,
             .data = .{ .table_row = .{
-                .cells = table_row.cells,
+                .cells_buffer = table_row.cells_buffer,
+                .cells_len = table_row.cells_len,
             } },
             .rest = "",
         };
@@ -606,7 +617,8 @@ fn startListItem(unindented_line: []const u8) ?ListItemStart {
 }
 
 const TableRowStart = struct {
-    cells: std.BoundedArray([]const u8, max_table_columns),
+    cells_buffer: [max_table_columns][]const u8,
+    cells_len: usize,
 };
 
 fn startTableRow(unindented_line: []const u8) ?TableRowStart {
@@ -615,15 +627,16 @@ fn startTableRow(unindented_line: []const u8) ?TableRowStart {
         mem.endsWith(u8, unindented_line, "\\|") or
         !mem.endsWith(u8, unindented_line, "|")) return null;
 
-    var cells: std.BoundedArray([]const u8, max_table_columns) = .{};
+    var cells_buffer: [max_table_columns][]const u8 = undefined;
+    var cells: ArrayList([]const u8) = .initBuffer(&cells_buffer);
     const table_row_content = unindented_line[1 .. unindented_line.len - 1];
     var cell_start: usize = 0;
     var i: usize = 0;
     while (i < table_row_content.len) : (i += 1) {
         switch (table_row_content[i]) {
             '\\' => i += 1,
             '|' => {
-                cells.append(table_row_content[cell_start..i]) catch return null;
+                cells.appendBounded(table_row_content[cell_start..i]) catch return null;
                 cell_start = i + 1;
             },
             '`' => {
@@ -641,20 +654,21 @@ fn startTableRow(unindented_line: []const u8) ?TableRowStart {
             else => {},
         }
     }
-    cells.append(table_row_content[cell_start..]) catch return null;
+    cells.appendBounded(table_row_content[cell_start..]) catch return null;
 
-    return .{ .cells = cells };
+    return .{ .cells_buffer = cells_buffer, .cells_len = cells.items.len };
 }
 
 fn parseTableHeaderDelimiter(
-    row_cells: std.BoundedArray([]const u8, max_table_columns),
-) ?std.BoundedArray(Node.TableCellAlignment, max_table_columns) {
-    var alignments: std.BoundedArray(Node.TableCellAlignment, max_table_columns) = .{};
-    for (row_cells.slice()) |content| {
+    row_cells: []const []const u8,
+    buffer: []Node.TableCellAlignment,
+) ?[]Node.TableCellAlignment {
+    var alignments: ArrayList(Node.TableCellAlignment) = .initBuffer(buffer);
+    for (row_cells) |content| {
         const alignment = parseTableHeaderDelimiterCell(content) orelse return null;
         alignments.appendAssumeCapacity(alignment);
     }
-    return alignments;
+    return alignments.items;
 }
 
 fn parseTableHeaderDelimiterCell(content: []const u8) ?Node.TableCellAlignment {
@@ -928,8 +942,8 @@ const InlineParser = struct {
     parent: *Parser,
     content: []const u8,
     pos: usize = 0,
-    pending_inlines: std.ArrayListUnmanaged(PendingInline) = .empty,
-    completed_inlines: std.ArrayListUnmanaged(CompletedInline) = .empty,
+    pending_inlines: ArrayList(PendingInline) = .empty,
+    completed_inlines: ArrayList(CompletedInline) = .empty,
 
     const PendingInline = struct {
         tag: Tag,

lib/std/Io.zig

@@ -231,21 +231,6 @@ pub fn GenericReader(
             return @errorCast(self.any().readBytesNoEof(num_bytes));
         }
 
-        pub inline fn readIntoBoundedBytes(
-            self: Self,
-            comptime num_bytes: usize,
-            bounded: *std.BoundedArray(u8, num_bytes),
-        ) Error!void {
-            return @errorCast(self.any().readIntoBoundedBytes(num_bytes, bounded));
-        }
-
-        pub inline fn readBoundedBytes(
-            self: Self,
-            comptime num_bytes: usize,
-        ) Error!std.BoundedArray(u8, num_bytes) {
-            return @errorCast(self.any().readBoundedBytes(num_bytes));
-        }
-
         pub inline fn readInt(self: Self, comptime T: type, endian: std.builtin.Endian) NoEofError!T {
             return @errorCast(self.any().readInt(T, endian));
         }

lib/std/Io/DeprecatedReader.zig

@@ -249,33 +249,6 @@ pub fn readBytesNoEof(self: Self, comptime num_bytes: usize) anyerror![num_bytes
     return bytes;
 }
 
-/// Reads bytes until `bounded.len` is equal to `num_bytes`,
-/// or the stream ends.
-///
-/// * it is assumed that `num_bytes` will not exceed `bounded.capacity()`
-pub fn readIntoBoundedBytes(
-    self: Self,
-    comptime num_bytes: usize,
-    bounded: *std.BoundedArray(u8, num_bytes),
-) anyerror!void {
-    while (bounded.len < num_bytes) {
-        // get at most the number of bytes free in the bounded array
-        const bytes_read = try self.read(bounded.unusedCapacitySlice());
-        if (bytes_read == 0) return;
-
-        // bytes_read will never be larger than @TypeOf(bounded.len)
-        // due to `self.read` being bounded by `bounded.unusedCapacitySlice()`
-        bounded.len += @as(@TypeOf(bounded.len), @intCast(bytes_read));
-    }
-}
-
-/// Reads at most `num_bytes` and returns as a bounded array.
-pub fn readBoundedBytes(self: Self, comptime num_bytes: usize) anyerror!std.BoundedArray(u8, num_bytes) {
-    var result = std.BoundedArray(u8, num_bytes){};
-    try self.readIntoBoundedBytes(num_bytes, &result);
-    return result;
-}
-
 pub inline fn readInt(self: Self, comptime T: type, endian: std.builtin.Endian) anyerror!T {
     const bytes = try self.readBytesNoEof(@divExact(@typeInfo(T).int.bits, 8));
     return mem.readInt(T, &bytes, endian);

lib/std/Io/Reader/test.zig

@@ -349,24 +349,3 @@ test "streamUntilDelimiter writes all bytes without delimiter to the output" {
 
     try std.testing.expectError(error.StreamTooLong, reader.streamUntilDelimiter(writer, '!', 5));
 }
-
-test "readBoundedBytes correctly reads into a new bounded array" {
-    const test_string = "abcdefg";
-    var fis = std.io.fixedBufferStream(test_string);
-    const reader = fis.reader();
-
-    var array = try reader.readBoundedBytes(10000);
-    try testing.expectEqualStrings(array.slice(), test_string);
-}
-
-test "readIntoBoundedBytes correctly reads into a provided bounded array" {
-    const test_string = "abcdefg";
-    var fis = std.io.fixedBufferStream(test_string);
-    const reader = fis.reader();
-
-    var bounded_array = std.BoundedArray(u8, 10000){};
-
-    // compile time error if the size is not the same at the provided `bounded.capacity()`
-    try reader.readIntoBoundedBytes(10000, &bounded_array);
-    try testing.expectEqualStrings(bounded_array.slice(), test_string);
-}

lib/std/Progress.zig

@@ -1006,7 +1006,7 @@ fn serializeIpc(start_serialized_len: usize, serialized_buffer: *Serialized.Buff
                         continue;
                     }
                     const src = pipe_buf[m.remaining_read_trash_bytes..n];
-                    std.mem.copyForwards(u8, &pipe_buf, src);
+                    @memmove(pipe_buf[0..src.len], src);
                     m.remaining_read_trash_bytes = 0;
                     bytes_read = src.len;
                     continue;